1. Technical Field
The present invention relates to an image display device, an image display method, and an image display program.
2. Related Art
Regarding an automatic image correction function with respect to a screen frame in a projector, there are known, for example, a technology described in JP-A-2005-286572 (Document 1) and a technology described in JP-A-2008-211354 (Document 2).
In the technology described in Document 1, there is disclosed, for example, an image processing system including an image projection device adapted to project an image toward a rectangular projection object (e.g., a screen) via a projection panel, a position adjustment information generation device adapted to generate position adjustment information based on a position adjustment of the image performed by the user, a correction information generation device adapted to generate position correction information for correcting the positions of the four corners of the image in the projection object based on the position adjustment information, and a correction device adapted to correct image information for projecting the image based on the position correction information, wherein the correction information generation device calculates the aspect ratio of the projection object based on the position adjustment information in the state in which the four corners of the image and the four corners of the projection object coincide with each other due to the position adjustment of the image performed by the user, and then generates the position correction information so that the image has a predetermined aspect ratio based on the aspect ratio thus calculated (see, e.g. Claim 1 of Document 1).
In the technology described in Document 2, there is disclosed, for example, a projector including a projection section adapted to project a calibration image toward a projection object via a projection panel, a shape determination section adapted to determine the shape of at least a part of the projection object based on one of imaging information from an imaging section in the state in which the calibration image is projected on the projection object and operation information from an operation section in that state, a correction target area setting section adapted to set a correction target area, which is an area following the shape determined by the shape determination section and is an area in the projection panel, an aspect ratio calculation section adapted to calculate the aspect ratio of the correction target area, a determination section adapted to determine whether or not a value representing a difference between the aspect ratio of the correction target area and a reference aspect ratio fulfills a preset condition, and an image generation section adapted to generate an image on the projection panel so as to have the shape of the correction target area in the case in which the preset condition is fulfilled and generate an image with the reference aspect ratio on the projection panel in the case in which the preset condition fails to be fulfilled (see, e.g. Claim 1 of Document 2).
However, in the automatic image correction function with respect to the screen frame in the projector according to the related art described above, a fixed aspect ratio having previously been determined such as the aspect ratio of the liquid crystal panel is used as the aspect ratio (or the reference thereof) of the corrected shape of the image.
Therefore, there arises a problem that the projection video is projected at an aspect ratio different from the aspect ratio of the input video, and thus the impression of the video varies in some cases.
Further, in the case in which both of the aspect ratio of the screen and the aspect ratio of the input video are vertically longer than the fixed aspect ratio (the aspect ratio of the panel) of the projector, gaps are formed between the screen and the corrected shape of the video at the top and the bottom, and gaps are formed between the corrected shape of the video and the projection video on the right and the left, and therefore, the large gaps are formed on the right, left, top, and bottom of the projection video to thereby shrink the projection video.
In contrast, in the case in which the fixed aspect ratio (the aspect ratio of the panel) of the projector is vertically longer than the aspect ratio of the screen and the aspect ratio of the input video, large gaps are similarly formed on the right, left, top, and bottom of the projection video to thereby shrink the projection video.
FIG. 6A is a diagram showing an appearance of the case in which the screen and the input video are vertically longer than the projector (panel). Such a case can occur in the case in which, for example, the user who owns the screen, the input video, and the projector as a set replaces the projector alone by purchase.
In this example, the aspect ratio of the screen and the aspect ratio of the input video are each 4:3 ((horizontal dimension):(vertical dimension)), and the aspect ratio of the projector is 16:9 ((horizontal dimension):(vertical dimension)).
FIG. 6A shows an example of a screen frame 501, a corrected shape 502 of a video, and a projection video 503. The gaps are formed on the right, left, top, and bottom of the projection video 503 with respect to the screen frame 501.
FIG. 6B is a diagram showing an appearance of the case in which the projector (panel) is vertically longer than the screen and the input video. Such a case can occur in the case in which, for example, the user who owns the screen, the input video, and the projector as a set replaces the screen and the input video (a device for generating the input video) by purchase.
In this example, the aspect ratio of the screen and the aspect ratio of the input video are each 16:9 ((horizontal dimension):(vertical dimension)), and the aspect ratio of the projector is 4:3 ((horizontal dimension):(vertical dimension)).
FIG. 6B shows an example of a screen frame 511, a corrected shape 512 of a video, and a projection video 513. The gaps are formed on the right, left, top, and bottom of the projection video 513 with respect to the screen frame 511.